Sternal wall pressure comparable to leaning during CPR impacts intrathoracic pressure and haemodynamics in anaesthetized children during cardiac catheterization

Aim

Force due to leaning during cardiopulmonary resuscitation (CPR) negatively affects haemodynamics and intrathoracic airway pressures (ITP) in animal models and adults, but has not been studied in children. We sought to characterize the effects of sternal force (SF) comparable to leaning force on haemodynamics and ITP in anaesthetized children.

Methods

Children (6 months to 8 yrs) presenting for routine haemodynamic cardiac catheterization with anaesthesia and mechanical ventilation >6 months after cardiac transplant were studied. Haemodynamics and ITP were measured before and during incremental increases in SF of 10% and 20% body weight.

Results

20 subjects (5.4 ± 1.7 yrs of age and 18.3 ± 3.3 kg) were studied. Mean right atrial pressure (6.5 ± 2.6 at baseline vs. 7.7 ± 2.6 at 10% SF vs. 8.6 ± 2.7 mmHg at 20% SF), mean pulmonary capillary wedge pressure (10.2 ± 2.9 at baseline vs. 11 ± 3.3 at 10% SF vs. 11.8 ± 3.4 mmHg at 20% SF) and ITP (16.3 ± 3.2 at baseline vs. 17.9 ± 3.9 at 10% SF vs. 19.5 ± 4 cm H₂O) all increased significantly with incremental SF (p < 0.001 for all). Aortic systolic pressure (85 ± 10 mmHg at baseline vs. 83 ± 10 mmHg at 10% SF vs. 82 ± 10 mmHg at 20% SF, p = 0.014) and coronary perfusion pressure (42 ± 7 mmHg at baseline vs. 39 ± 7 mmHg at 10% SF vs. 38 ± 7 mmHg at 20% SF, p < 0.001) both decreased significantly with incremental SF.

Conclusions

In asymptomatic, anaesthetized children after cardiac transplantation, sternal forces comparable to leaning previously reported to occur during CPR elevate ITP and right atrial pressure and decrease coronary perfusion pressure. These haemodynamic effects may be clinically important during CPR and warrant further study.